Plastic container and closure and method of forming the same



1966 R. D. LURIE 3, 76,

PLASTIC CONTAINER AND CLOSURE AND METHOD OF FORMING THE SAME Filed Feb. 5, 1964 INVENTOR RQNDOLPH D. LUR\E BY 777 fm-i, K/O'W ATTORNEYS United States Patent 3,276,616 PLASTIC CONTAINER AND CLOSURE AND METHOD OF FORMING THE SAME Randolph D. Lurie, Park Forest, Ill., assignor to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed Feb. 5, 1964, Ser. No. 342,673 12 Claims. (Cl. 22027) This invention relates to a novel container and closure, and to a novel method of securing the closure to the container which is characterized by an effective hermetic seal between the closure and the container, the relatively easy opening of the container by the removal of the closure, and the relative ease of reclosing the closure and the container after the container has been once opened.

It is conventional in the packaging industry to package a desirable fill or product in a container, introduce a gaseous preservative into the container, and then seal a closure to the container. Such containers and closures are constructed from a variety of different materials, such as plastic, paper, metal foil, etc., the selection of which depends upon such factors as the cost of the raw material, the ease of manufacture, the nature of the product to be packaged in the containers, the desired or required shelflife of the product, and many other variables. Where product visability is desirable, the closures are generally constructed from relatively thin lightweight transparent or translucent plastic film material, while the bodies of the containers are generally constructed from material of a heavier gauge and of a greater strength.

Irrespective of the variety of container and closure arrangements which are possible it is generally desirable from the standpoint of consumer acceptance to provide containers of the type which satisfy three essential characteristics.

First, the closures associated with the containers must be effectively hermetically sealed'to the bodies of the containers to hold the gaseous preservative in the containers, thereby preventing product-spoilage and maintaining or increasing the desired shelf-life of the product.

Secondly, such closures should be easily removed'from the container bodies to permit rapid and unobstructed access to the product packaged in the containers.

Finally, after the closures have been once removed from the containers, the containers should be capable of being easily reclosed by the reapplication of the original closures to the containers.

Various prior art container structures possess one or more of these desirable characteristics, but in general, the inclusion of one of the characteristics in a container structure necessitates the omission of one or the remainder of these three aforementioned characteristics. Absent an actual omission of structure which provides a hermetic seal, easy opening and easy reclosure of such containers, the effectiveness of such structure is generally inadequate to achieve each of the desired functions. In those cases where all three of these latter-mentioned characteristics are incorporated in a container structure, they are usually obtained by intricate and time consuming manufacturing procedures, costly raw materials, and other major disadvantages which discourage the manufacture of an eflicien-t low cost container structure which embodies each of the noted characteristics.

3,276,616 Patented Oct. 4, 1966 It is, therefore, an object of this invention to provide a novel method which eliminates the above-noted and other disadvantages, and which alfords the production of a low cost, efiiciently hermetically sealed, easily openable and reclosable container and closure structure.

A further object of this invention is to provide a novel container and closure structure comprising a container body having a weakened radius portion and means securing a closure to the weakened radius portion and facilitating the unified removal of the closure and a portion of the radius portion from the container body whereby the removal of the closure along the weakened radius portion opens the container and permits the reuse of the closure to reclose the once opened container.

Still another object of this invention is to provide a novel combined container and closure comprising a container body having a bottom wall and an upper end portion, the upper end portion being reversely directed toward the bottom wall to define a peripheral flange joined to the container body at a radius portion, a closure, means securing the closure to the container body at the radius portion, and means facilitating the unified removal of the closure and the flange from the container body at the radius portion whereby the removal of the flange opens the upper end portion of the container body and forms a reclosure defined by the removed unified closure and flange.

A further object of this invention is the provision of a novel combined container and closure of the type immediately above-described in which the means facilitating the unified removal of the closure and the flange is a weakened area at the radius portion, and the securing means is an area of fusion between the closure and the radius portion.

A further object of this invention is to provide a novel combined container and closure of the type just described in which the weakened area at the radius portion is a peripheral coined indentation and the area of fusion is a weld portion formed from the material of both the radius portion and the closure.

A further object of this invention is to provide a novel method of applying a closure to an upper end portion of a container body including the steps of reversely directing an upper end portion of a container body toward a bottom wall thereof to form a peripheral flange joined to the body at a radius portion, and securing a closure solely to the radius portion in a manner which permits the unified removal of the flange and the closure incident to the opening of the container body.

A further object of this invention is to provide a novel method of applying a closure to a container body comprising the steps of weakening a peripheral portion of an upper end portion of a container body remote from a terminal edge thereof, bending the upper end portion about the peripheral portion to form a peripheral flange joined to body at a peripheral radius portion, and securing a closure to the radius portion adjacent the peripheral portion by a spin-welding operation to permit the unified removal of the flange and the closure incident to the removal of the closure from the container body.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawing.

In the drawing:

FIGURE 1 is a top perspective view of a novel container and closure constructed in accordance with this invention, and illustrates the closure secured to an upper end portion of the container.

FIGURE 2 is an enlarged fragmentary sectional view taken along line 2-2 of FIGURE 1, and illustrates the closure joined at a weakened radius portion between a container body and an exterior peripheral flange of the container.

FIGURE 3 is an enlarged fragmentary sectional view of the container and closure, similar to FIGURE 2, and illustrates the initiation of a tear in the weakened radius portion to remove the closure from the container body.

FIGURE 4 is a fragmentary sectional view of the container and closure of this invention, and illustrates the closure being reapplied to the container after having been once removed therefrom.

FIGURE 5 is a fragmentary sectional view of a die, and illustrates the formation of a coined indentation in the radius portion of the container and the substantial bending of the flange.

FIGURE 6 is a schematic sectional view of a forming die and illustrates the coined flange being directed toward a bottom wall of a container.

FIGURE 7 is a fragmentary sectional schematic view of the forming die of FIGURE 6, and illustrates a closure being secured to the weakened radius portion of the container by a spin-welding operation.

FIGURE 8 is a fragmentary cross-sectional schematic view of the forming die of FIGURES 6 and 7, and illustrates the application of an adhesive to the radius portion of a container body prior to the application of a closure thereto.

A novel combined container and closure constructed in accordance with this invention is best illustrated in FIGURES 1 and 2 of the drawing, to which attention is now directed, and is generally designated by the reference numeral 10. The combined container and closure 10 includes a closure 11 and a container 12, both of which are constructed from plastic material, such as polyethylene, polycarbonate, modified high impact strength polystyrene or similar plastic which can be readily drawn at room temperature.

The container 12 comprises a body or wall 13 (FIG- URE 1) which gradually tapers downwardly and terminates in a bottom wall (not shown). An upper end portion 14 of the container body 16 is reversely directed radially outwardly and downwardly toward the bottom wall to define an external peripheral flange or skirt joined to the container body 13 at a peripheral radius portion 16. A uniform peripheral gap or space 17 separates the depending flange 15 from the container body 13, as is best illustrated in FIGURE 2 of the drawing. The flange 15 terminates in a free edge 18 remote from the bottom wall (not shown) of the container body 13 and closely adjacent the radius portion 16.

A coined indentation or groove 20 is formed in the underside of the radius portion '16 (FIGURE 2) to form a peripherally weakened area which facilitates the removal of the flange 15 from the container body 13 in a manner to be described more fully hereafter. The coined indentation 20 reduces the thickness of the radius portion 16 from the original thickness thereof (approximately 0.010 inch or greater) to a thickness of approximately 0.001 to 0.003 inch.

The closure 11 is a planar circular disc having a peripheral edge 21 and a lower surface 22. The lower surface 22 rests upon and is secured to the peripheral radius portion 16 of the container 12 by a peripheral area of fusion 23 between the lower surface 22 of the closure 11 and the radius portion 16 of the container body 13. The area of fusion 23 can be a peripheral area of heat sealing, but is preferably a weld formed from the fused material of both the radius portion 16 and the closure 11 by a spinwelding operation. The closure 11 can, however, be secured to the radius portion 16 at the area of fusion 23 by a conventional adhesive or similar securing means which assures a hermetic seal between the closure 11 and the container 12 upon the original application of the closure 11 to the radius portion 16 of the container body 13.

The combined container and closure 10 shown in FIG- URE 2 of the drawing is opened to gain access to the interior of the container 12 and any product or fill packaged therein in a manner clearly illustrated in FIGURE 3. The container 12 is opened by lifting or pulling the flange 15 radially upwardly and outwardly in the direction of the directional arrow of FIGURE 2 to initially sever or rupture the radius portion 16 at the peripherally weakened or coined area 20. As the closure 11 is continually and progressively lifted in the manner illustrated in FIGURE 3 of the drawing, the closure 11 is peeled away from the container body '13 along a portion 24 of the peripheral area of fusion 23 radially innermost from the peripheral groove 20 (FIGURE 3). This peeling continues until the entire peripheral extent of the portion 24 is severed from the container body 13 at which time the closure 11 is completely removed from the container 12. It should be particularly noted that the depending peripheral flange or skirt 15 remains secured to the closure 11 during this removal of the closure 11 from the container 12. That is, the reduced thickness of the radius portion 16 in the area of the coined indentation 20 permits relatively easy tearing or peeling along the portion 24 yet facilitates the unified removal of the closure 11 and the depending peripheral flange or skirt 15. Thus, the removal of the closure 11 from the container body 13 substantially simultaneously opens the upper end portion 14 thereof to permit unobstructed access into the interior of the container 12 and forms a reclosure 19 (FIGURE 4) defined by the closure 11 and the unified flange 15 of the container 12.

The container 12 of FIGURE 4 can now be reclosed by the reclosure 19 in a manner clearly illustrated in this figure, to close the upper end portion 14 thereof and prevent access to the interior of the container body 13 and the product or fill packaged therein.

The container 12 of FIGURES 1 through 4 of the drawing is formed by first cutting a blank of suitable plastic material to proper size and drawing this blank in a conventional manner to form a relatively shallow drawn container body. The blank or sheet of plastic material is placed between upper and lower portions of a conventional die assembly and the plastic material is clamped between a draw punch and a drawn ring thereof. Simultaneously with this clamping action, the plastic material is trimmed by the cutting action of the draw punch which forces the plastic material past a shear fitting closely around the outside of the draw punch, thus causing the plastic material to be cut cleanly and uniformly.

The portion of the blank which forms the container wall is drawn from the material which is clamped between the draw punch and the draw ring. The downward progress of the draw punch and the draw ring causes this material to be drawn into a narrow space between the draw punch and a conventional die center pad of the die assembly. At the completion of this first operation, the container body is withdrawn from the die assembly for subsequent operations. At this time, the container body comprises a generally shallow container wall which may terminate in a flange formed from the material clamped between the draw punch and the draw ring.

A second operation is then performed to convert the shallow container body to a container body of greater depth and smaller diameter. The second operation redraws, to a greater depth, the container body which has already been formed.

In this second operation, the shallow container body is placed over a draw ring and die center pad of another conventional die assembly. During the progress of the redrawing operation, material is drawn from the material which is conventionally clamped between the draw punch and the draw ring into the space between the draw punch and the die center pad, thus forming the wall of the redrawn container body. As material is drawn from between the draw punch and the draw ring, new material is drawn from outside the draw ring into this clamped area to replace the material which has been removed. This new material drawn into the clamping area of the draw punch and the draw ring comes from that material which had been used to form the container wall during the first operation. This process usually continues until all of the material outside the draw ring has been drawn into the area between the draw punch and the draw ring.

At the completion of this second redrawing operation, not all of the plastic material has been drawn into the space between the draw punch and the die center pad, and a flange remains around an opened mouth of the redrawn container body. This is flange which corresponds to the flange of FIGURES 1 through 4 prior to being reversely directed downwardly toward the bottom wall of the container 12 and prior to the formation of the peripheral weakened area at the radius portion 16 joining the flange 15 to the container wall 13.

The weakened area is now formed in the radius portion joining the flange of the redrawn container to the body wall thereof by a die assembly of FIGURE 5. The die assembly 25 comprises a male member or die 26 and a female member or die 27. The male and female dies, 26 and 27 respectively, are arranged in axial alignment and are relatively reciprocally mounted in a conventional press in a manner well known in the prior art and forming no part of this novel invention.

The male die 26 includes a draw punch 29 which is substantially circular in transverse section and has an upper exterior peripheral wall 28. A downwardly facing inclined annular wall 30 of the male die 26 blends in a radius portion 31 which in turn terminates at a peripheral wall 32 of a substantially cylindrical punch 33. The punch 33 establishes the inside diameter of a container body at an upper end portion thereof in a manner which will be described more fully hereafter.

The female die 27 has a vertical bore 34 defined by an interior peripheral wall 35. The bore 34 of the female die 27 is in axial alignment with the punch 33 of the male die.26 and the interior peripheral wall 35 of the female die 27 establishes the exterior diameter of the container body.

An upper exterior peripheral wall '36 of the female die 27 is in alignment with the upper peripheral wall 28 of the male die 26 to define therewith a substantially unbroken external peripheral surface of the die assembly 25. The upper exterior peripheral wall 36 of the female die 27 terminates at an upwardly facing inclined annular wall 37 opposing the downwardly facing inclined wall 30 of the male die 26. An upwardly projecting circumferential shoulder or ridge 38 is located at the juncture of the upwardly facing inclined wall 37 and the interior peripheral wall 35 of the female die 27. A pair of upwardly converging circumferential wall portions (unnumbered) of the shoulder or ridge 38 set off a relatively sharp circumferential apex 40 having an included angle of substantially thirty degrees. The circumferential apex 40 opposes the downwardly facing radius portion 31 of the male die 26.

A shear 41 is normally immovably mounted in the die assembly 25 in any conventional manner surrounding the exterior peripheral surface 36 of the female die 27. The shear 41 terminates in a circumferential shearing or trimming edge 42 which cooperates with the exterior peripheral walls 28 and 36 of the respective male and female dies 26 and 27 in a manner to be described immediately hereafter.

In describing the operation of the die assembly 25 it is to be understood that the die assembly 25 is first placed into a conventional press (not shown) and thereafter the press is actuated to space the male die 26 a considerable distance above the female die 27. At this time the shear 41 surrounds the exterior peripheral wall 36 of the female die 27. A conventional air cushion or a plurality of compression springs acting against the underside of the female die 27 forces the female die to rise upwardly from the position in FIGURE 5 in this aforementioned surrounding relationship with the shear 41.

At this time, a plastic container 43 having a cylindrical wall or body 44 joined to an outwardly directed radial flange 45 by a peripheral radius portion 46 is inserted into the female die 27 of the die assembly 25. The container 43 is preferably constructed from polyethylene, polypropylene or similar plastic materials, and has already been redrawn in the manner heretofore described.

The press (not shown) is then closed in a conventional manner forcing the punch 33 of the male die 26 into the opened upper end portion (unnumbered) of the container body 44. As the punch 33 descends, the flange 45 of the container body 44 is forceably clamped between the 0pposed walls '30 and 37 of the respective male and female dies 26 and 27. This clamping pressure forces the upwardly projecting circumferential ridge 38 of the female die 27 into the underside of the radius portion 46 which causes an indentation 47 to be coined into the undersurface of the radius portion 46 completely around the circumference of the container body 44. Simultaneously with this coining action, the flange 45 of the container 43 is directed downwardly toward the bottom wall (no-t shown) of the container 43 at an angle of approximately forty degrees.

As the punch 33 and the female die 27 are further depressed against the air cushion or compression springs acting against the underside of the female die 27, the female die 27 continually moves downwardly as viewed in FIGURE 5 against the force of the conventional air cushion or compression springs. The descent of the female die 27 under the influence of the male die 26 urges the flange 45 of the container 43 beyond the shearing edge 42 of the shear 41 to the position illustrated in FIGURE 5, thereby shearing or trimming the flange 45 in the manner clearly illustrated in this figure. During this shearing operation, the exterior peripheral walls 28 and 36 of the respective male and female dies 26 and 27 cooperate with the trimming edge 42 of the shear 41 to evenly trim the flange 45.

After the flange 45 of the container body 44 has been trimmed, the press is opened in a conventional manner, and the container 43 is removed from the female die 27, at which time the container 43 is in condition to be packaged with a desirable fill or product and thereafter closed. To this end, the container 43 is positioned on a suitable support 50 (FIGURE 6) beneath an annular forming die 51 which is normally positioned with a forming rib 52 thereof above the radius portion 46 of the container 43. The annular forming die 51 is reciprocated downwardly from this latter position by a conven tional mechanism is a manner such that an arcuate forming surface 53 of the rib 52 directs the flange 45 from the position illustrated in FIGURE 5 to the position shown in FIGURE 6. The desired product or fill can be packaged in the container 43 prior to, simultaneously with or immediately after this forming of the flange 45.

After a gaseous preservative is introduced into the container 43, a rotating spinning head 54 of a conventional spin-Welding apparatus (not shown) is reciprocated downwardly to the position illustrated in FIGURE 7. The spin head 54 carries a closure 55, similar to the closure 11, which is fused or spin-welded to the radius portion 46 of the container 43 by the rapid rotation of the spin head 54 in a manner well known in the prior art. At the completion of the spinning operation, the spin head 54 is retracted upwardly along with the annular forming 17 die 51 and the container 43, with the closure 55 hermetically sealed thereto, is removed from the support 50 for subsequent shipment or storage.

A container 56 of FIGURE 8 of the drawing is shown positioned in a forming die 57 which is identical to the forming die 51 of FIGURE 6. The container 56 is identical to the containers 12 and 43, but in lieu of the spin-welding operation illustrated in FIGURE 7, a closure 58 is secured to a peripheral radius portion of the container 56 by the application of an adhesive A from a conventional adhesive applicator 60 to the radius portion (unnumbered) of the container 56. The closure 58 is carried in a conventional manner by a conventionally reciproca-ted head 61 which moves downwardly from the position illustrated in FIGURE 8 to seat the closure 58 upon the radius portion of the container 56. It should be particularly noted that the head 61 is merely reciprocal and no rotation thereof takes place. In this manner, the closure 58 is adhesively secured to the radius portion (unnumbered) of the container 56 to form a combined container and closure substantially identical to the combined container and closure 10 of FIGURES 1 through 3 of the drawing.

While examples of a preferred form of the die assembly and the forming die are disclosed herein, as well as a preferred method and a novel article produced thereby, it is to be understood that variations in the die assemblies, the method and the article may be made without departing from the spirit and scope of this invention.

For example, while the die assembly of FIGURE 5 is constructed to produce a generally cylindrical article or container, this disclosed die assembly is merely exemplary and a die assembly capable of forming non-cylindrical containers, i.e., square, oblong, pear-shaped, etc., is within the scope of this invention. The novel non-cylindrical containers formed by such a die, as well as the method of so forming such containers, is also deemed part of this invention. Therefore, any generally tubular container, either cylindrical or non-cylindrical, forms a part of this invention.

In the case of such non-cylindrical containers, the closure associated with such containers would correspond to the general transverse cross-sectional configuration thereof and such closures would be secured to the noncylindrical containers by heat sealing, adhesive sealing or solvent welding,-rather than by a spin welding operation which would apply generally only to round or cylindrical containers.

While the container is preferably formed by pressdrawing, it is also to be understood that the container of this invention can also be formed by other conventional forming methods, such as vacuum forming, injection molding or blow molding.

From the foregoing, it will be seen that novel and advantageous provisions have been made by carrying out the desired end. However, attention is again directed to the fact that additional variations may be made in this invention without departing from the spirit and scope thereof as defined in the appended claims.

I claim:

1. A combined container and closure comprising a container body having a bottom wall and an upper end portion, said upper end portion being reversely bent radially outwardly and downwardly toward the bottom wall to define a peripheral flange joined to the container body at a bent radius portion, a closure, means securing the closure to the container body at the radius portion, and means facilitating the unified removal of the closure and the flange from the container body at the radius portion whereby the removal of said flange from the container body opens the upper end portion thereof and forms a reclosure defined by the removed unified closure and flange.

2. The combined container and closure as defined in claim 1 wherein the means facilitating the unified removal of the closure and the flange is a weakened area at the radius portion.

3. The combined container and closure as defined in claim 1 wherein the securing means is an area of fusion between the closure and the radius portion.

4. The combined container and closure as defined in claim 1 wherein the means facilitating the unified removal of the closure and the flange is a weakened area at the radius portion, and the securing means is an area of fusion between the closure and the radius portion.

5. The combined container and closure as defined in claim 2 wherein the weakened area at the radius portion is an indentation.

6. The combined container and closure as defined in claim 3 wherein the area of fusion is a weld portion formed from the material of both the radius portion and the closure.

7. The combined container and closure as defined in claim 4 wherein the weakened area at the radius portion is an indentation and the area of fusion as a weld portion formed from the material of both the radius portion and the closure.

8. A combined plastic container and closure comprising a container body having a bottom wall and an upper end portion, said upper end portion being reversely bent radially outwardly and downwardly toward the bottom wall to define a peripheral flange surrounding the container body and joined thereto at a peripheral radius portion, a planar closure of a predetermined thickness seated upon said peripheral radius portion, means securing said closure to a peripheral area of radius portion, and a coined peripheral indentation in said radius portion underlying the peripheral area of securement between the closure and the radius portion whereby the flange and closure are removed in unison from the container body when the radius portion is severed along the coined indentation to simultaneously open the upper end portion of the container body and form a reclosure defined by the removed unified closure and flange.

"9. A combined plastic container and closure comprising a container body having a bottom wall and an upper end portion, said upper end portion being reversely bent radially outwardly and downwardly toward the bottom Wall to define a peripheral flange surrounding the container body and joined thereto at a peripheral bent radius portion, a closure of a predetermined thickness seated upon said bent radius portion, a peripheral area of fused material of said closure and said bent radius portion securing said closure to said container body at said bent radius portion, a coined peripheral indentation in said bent radius portion underlying the peripheral area of securement between the closure and the radius portion whereby the flange and closure are removed in unison from the container body when the radius portion is severed along the coined indentation to simultaneously open the upper end of the container body and form .a reclosure defined by the removed unified closure and flange, and said peripheral area of fusion additionally securing the closure to the container body inwardly of the coined peripheral indentation.

10. A method of applying a closure to an upper end portion of a container body comprising the steps of providing a container body including a body wall having an upper end portion terminating in a terminal edge, reversely bending the upper end portion of the container body toward the bottom wall thereof to form a peripheral flange joined to the body at a radius portion with the upper end portion directed toward the bottom wall, and securing a closure to the radius portion.

11. A method of applying a closure to an upper end portion of a container body comprising the steps of providing a container body including a body wall having an upper end portion terminating in a terminal edge, weakening a peripheral portion of the upper end portion remote from the terminal edge, reversely bending the upper end portion of the container body about the peripheral weakened portion toward the bottom Wall thereof to form a peripheral flange joined to the body at a radius portion with the upper end portion directed toward the bottom Wall thereof to form a peripheral flange joined to the body at a radius portion with the upper end portion directed toward the bottom wall, and securing a closure to the radius portion.

12. The method as defined in claim 11 wherein the operation.

References Cited by the Examiner UNITED STATES PATENTS Hul-l 156-73 Hitzelberger 156-73 Hutchinson 220-54 Betner 220-54 Betner 220-54 THERON E. CONDON, Primary Examiner.

G. T. HALL, Assistant Examiner. 

1. A COMBINED CONTAINER AND CLOSURE COMPRISING A CONTAINER BODY HAVING A BOTTOM WALL AND AN UPPER END PORTION, SAID UPPER END PORTION BEING REVERSELY BENT RADIALLY OUTWARDLY AND DOWNWARDLY TOWARD THE BOTTOM WALL TO DEFINE A PERIPHERAL FLANGE JOINED TO THE CONTAINER BODY AT A BENT RADIUS PORITON, A CLOSURE, MEANS SECURING THE CLOSURE TO THE CONTAINER BODY AT THE RADIUS PORTION, AND MEANS FACILITATING THE UNIFIED REMOVAL OF THE CLOSURE AND THE FLANGE FROM THE CONTAINER BODY AT THE RADIUS PORTION WHEREBY THE REMOVAL OF SAID FLANGE FROM THE CONTAINER BODY OPENS THE UPPER END PORTION THEREOF AND FORMS A RECLOSURE DEFINED BY THE REMOVED UNIFIED CLOSURE AND FLANGE. 